This is my first post here, I have been racking my brain for about a week trying to get a customers C5500 rollback going. I have rebuilt the fuel filter head to no avail. Other issue I'm having is no top end power. Wont even pull itself at the speed limit in a 5 mph head wind. Zero codes, makes desired rail pressure and right at 17 psi of boost. This is a new long block, swapped injectors and all other parts from old engine(had 4 scored holes)
LB7 losing prime
- Thread starter ballisticdieselperf
- Start date
Sometimes rebuilding the filter head just doesnt work.
What did you do about the rubber lines on the engine?
What about the lines from the tank? They can develop pinholes that will pull air.
You should probably pressurize the fuel system slightly to find any possible leaks.
What did you do about the rubber lines on the engine?
What about the lines from the tank? They can develop pinholes that will pull air.
You should probably pressurize the fuel system slightly to find any possible leaks.
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Engine was running fine when it came in to get all the parts swapped over to the new long block. Its in a rollback tow truck, customer is an absolute pain in the ass. This is only the second LB7 I have ever worked on because I usually have plenty for ford and dodge work I just turn down the GM jobs because it seems like everything on a GM takes a special tool.
Could the issue be caused from a seal on the return system?
Could the issue be caused from a seal on the return system?
You should have just replaced the filter head instead of rebuilding it, just ran into two different Duramax lbz losing prime and in both cases it was the filter head replaced problem solved.
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